Reorganize source files of collab::db

* Move all sea_orm tables into a 'tables' module
* Move TestDb into its own file
* Move id types into their own module

crates/collab/src/db/tables/worktree_entry.rs

@@ -0,0 +1,29 @@
+use crate::db::ProjectId;
+use sea_orm::entity::prelude::*;
+
+#[derive(Clone, Debug, PartialEq, Eq, DeriveEntityModel)]
+#[sea_orm(table_name = "worktree_entries")]
+pub struct Model {
+    #[sea_orm(primary_key)]
+    pub project_id: ProjectId,
+    #[sea_orm(primary_key)]
+    pub worktree_id: i64,
+    #[sea_orm(primary_key)]
+    pub id: i64,
+    pub is_dir: bool,
+    pub path: String,
+    pub inode: i64,
+    pub mtime_seconds: i64,
+    pub mtime_nanos: i32,
+    pub git_status: Option<i64>,
+    pub is_symlink: bool,
+    pub is_ignored: bool,
+    pub is_external: bool,
+    pub is_deleted: bool,
+    pub scan_id: i64,
+}
+
+#[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]
+pub enum Relation {}
+
+impl ActiveModelBehavior for ActiveModel {}